Where a vane airfoil is part of a single stage turbine driving a fan or other output shaft (i.e. is part of a single stage LP turbine), as opposed to being part of multiple stage turbine, the requirements for such a vane airfoil design are significantly more stringent, as the fan/output shaft relies solely on this single stage LP turbine to deliver work, as opposed to work being spread over several turbine stages. Over and above this, the airfoil is subject to flow regimes which lend themselves easily to flow separation. Such a situation would limit the amount of work transferred to the fan/output shaft, and hence the total thrust (or power) capability of the engine. Further complicating the aerodynamic situation in a single stage LP turbine occurs where the LP vane follows a transonic high pressure turbine stage (HPT), and where a significant gaspath flare angle away from the engine center line, which is provided to improve work output of the turbine, but which then must be re-directed by the LP vane into being more parallel to the engine center line prior to entering the following LP blade passage. Therefore, improvements in airfoil design are sought